The People's Bank of China (PBC), the central bank, is studying ways of collecting and distributing data on how funds raised online are being used because of the risks posed, the director of its statistics department Sheng Song said in an essay released on Saturday.

Online peer-to-peer (P2P) lending platforms have expanded rapidly in China, along with an increasing number of fraud cases.

Last month, police arrested 21 executives at Zhongjin Capital Management - a Shanghai-based platform that promised retail investors double-digit returns for short-term projects - for alleged "illegal fundraising."

China's government has responded with a plan to clean up the country's online financial sector, including rules to limit the activities of P2P lending firms, sources with direct knowledge of the matter told Reuters on Friday.

In February, authorities arrested 21 officials from Ezubao, once China's biggest P2P lending platform that collected $7.6 billion in two years.